docs: def release_lock():
      """Release lock on compilation directory."""
      get_lock.n_lock -= 1
      assert get_lock.n_lock >= 0
      # Only really release lock once all lock requests have ended.
      if get_lock.lock_is_enabled and get_lock.n_lock == 0:
          get_lock.start_time = None
          get_lock.unlocker.unlock()